印度东北部特里普拉邦一家三级护理医院中耐多药金黄色葡萄球菌的评估及其与生物膜形成的关联
Evaluation of Multidrug Resistant Staphylococcus aureus and their Association with Biofilm Production in a Tertiary Care Hospital, Tripura, Northeast India.
作者信息
Bhattacharya Sibabrata, Bir Raunak, Majumdar Tapan
机构信息
Assistant Professor, Department of Microbiology, Agartala Government Medical College , Kunjavan, Agartala, Tripura, India .
Junior Resident, Department of Microbiology, Agartala Government Medical College , Kunjavan, Agartala, Tripura, India .
出版信息
J Clin Diagn Res. 2015 Sep;9(9):DC01-4. doi: 10.7860/JCDR/2015/13965.6417. Epub 2015 Sep 1.
BACKGROUND
High morbidity and mortality rates are associated with Methicillin-resistant Staphylococcus aureus (MRSA) because of development of multidrug resistance. Staphylococcus aureus (S. aureus) has the ability to colonize and form biofilms on biomaterials which is causing resistance towards antimicrobials and thus making them difficult to eradicate from the infected hosts.
MATERIALS AND METHODS
Culture isolation, identification was done following standard protocol and antibiogram of the isolates were done. The detection of MRSA, Macrolide-Lincosamide-Streptogramin B resistance (MLSB), vancomycin resistance phenotypes were done by using cefoxitin disc diffusion test, D zone test and vancomycin E test. Biofilm was detected by Congo red agar method.
RESULTS
A total of 100 (31.7%) S. aureus strains were isolated from 315 clinical specimens. The prevalence of MRSA was 47% (47/100) with 85.1% were homogeneous MRSA and 14.9% were heterogeneous. Out of 47 MRSA strains, 63.8% were Hospital acquired-MRSA (HA-MRSA) infections whereas rests 36.2% were caused by Community acquired-MRSA (CA-MRSA) strains. Maximum number of MRSA isolates belonged to group A biotype (34%). A 14.9% isolates were of nontypeable group. Out of 100 S. aureus isolates, the prevalence of Vancomycin resistant S. aureus (VRSA) was found to be 3%. The MLSB phenotypes showed that the rates of inducible MLSB (iMLSB), constitutive MLSB (cMLSB) and Macrolide-Streptogramin B (MSB) in case of MRSA to be 19.1%, 31.9% and 12.8%. Prevalence of low-level (MUP(L)) and high-level mupirocin resistance (MUP(H)) among MRSA was 19.1% and 6.4%. Biofilm production was found in 55% strains of S. aureus. Out of 47 MRSA strains 76.6%were producing biofilm in comparison to 38.8% in methicillin-sensitive S. aureus (MSSA). Higher degree of antibiotic resistance in biofilm producers was seen especially in case of ciprofloxacin, co-trimoxazole, rifampicin, kanamycin, erythromycin and clindamycin whereas gentamycin, tetracycline and penicillin resistance was more in non-biofilm producers.
CONCLUSION
This study shows high rate of circulating MRSA with a majority of these isolates are multi-drug resistant of which mostly are biofilm producers in our hospital setup. Development of antimicrobial stewardship program based on the local epidemiological data and national guidelines is the need of the hour.
背景
由于多重耐药性的发展，耐甲氧西林金黄色葡萄球菌（MRSA）的发病率和死亡率较高。金黄色葡萄球菌（S. aureus）能够在生物材料上定植并形成生物膜，这导致其对抗菌药物产生耐药性，从而使其难以从感染宿主中根除。
材料与方法
按照标准方案进行培养分离、鉴定，并对分离株进行药敏试验。采用头孢西丁纸片扩散法、D 试验和万古霉素 E 试验检测 MRSA、大环内酯-林可酰胺-链阳菌素 B 耐药性（MLSB）、万古霉素耐药表型。采用刚果红琼脂法检测生物膜。
结果
从 315 份临床标本中分离出 100 株（31.7%）金黄色葡萄球菌。MRSA 的患病率为 47%（47/100），其中 85.1%为同源性 MRSA，14.9%为异源性。在 47 株 MRSA 菌株中，63.8%为医院获得性 MRSA（HA-MRSA）感染，其余 36.2%由社区获得性 MRSA（CA-MRSA）菌株引起。MRSA 分离株数量最多的属于 A 组生物型（34%）。14.9%的分离株为不可分型组。在 100 株金黄色葡萄球菌分离株中，发现耐万古霉素金黄色葡萄球菌（VRSA）的患病率为 3%。MLSB 表型显示，MRSA 中诱导型 MLSB（iMLSB）、组成型 MLSB（cMLSB）和大环内酯-链阳菌素 B（MSB）的发生率分别为 19.1%、31.9%和 12.8%。MRSA 中低水平（MUP(L)）和高水平莫匹罗星耐药（MUP(H)）的患病率分别为 19.1%和 6.4%。55%的金黄色葡萄球菌菌株产生生物膜。在 47 株 MRSA 菌株中，76.6%产生生物膜，而甲氧西林敏感金黄色葡萄球菌（MSSA）中这一比例为 38.8%。生物膜产生菌的抗生素耐药程度更高，尤其是环丙沙星、复方新诺明、利福平、卡那霉素、红霉素和克林霉素，而非生物膜产生菌对庆大霉素、四环素和青霉素的耐药性更高。
结论
本研究表明，在我们医院环境中，循环 MRSA 的发生率较高，这些分离株大多具有多重耐药性，且大多为生物膜产生菌。根据当地流行病学数据和国家指南制定抗菌药物管理计划迫在眉睫。
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